Injection molding machine and method



Aug. 15, 1950 F. w. BLANCHARD ETAL ,5 8,

INJECTION MOLDING MACHINE AND METHOD Filed July 19, 1945 v 8Sheets-Sfieet 1 g- 1950 F. w. BLANCHARD ErAL 2,518,

xmmc'rzou MOLDING MACHINE AND METHOD "Filed July 19,1945 8 Sheet s-Sheet2 I Q'z formgys Aug. 15, 1950 F. W, BLANCHARD EI'AL INJECTION MOLDINGMACHINE AND METHOD a Shets-Sheet 5 Filed July 19, 1945 Aug. 15, 1950 F.w. BLANCHARD ETAL 2,518,

INJECTION MOLDING MACHINE AND METHOD 8 SheetsSheet 4 MFV/ (Hfam s NVEFiled July 19, 1945 Aug. 15, 1950 F. w. BLANCHARD' ETAL INJECTIONMOLDING MACHINE AND METHOD 8 Sheets-Sheet Filed July 19, 1945 g- 5 1950F. w. BLANCHARD ETIAL 2,518,

INJECTION MOLDING MACHINE AND METHOD Filed July 19, 1945 8 Sheets-Sheet7 F. w. BLANCHARD ETAL 2,518,594

INJECTION MOLDING MACHINE AND METHOD Aug. 15, 195 0 8 Sheets-Sheet 8Filed July 19, 1945 Patented Aug. 15, 1 950 INJECTION MOLDING MACHINEAND METHOD Francis 'W. Blanchard, Snyder, and Alfred C.

Borkenhagen, Bufialo, N. Y., assignors to Howitt Rubber Gorporation,Buffalo, N. Y.

Application July 19, 1945; Serial No. 605,906

This invention relates to iniection molding machines and methodsfor'molding articles from plastic materials. I

One of the objects of this invention is to provide a machine of thistype with means ofimproved construction for feeding charges of plasticmaterial to the molds. Another object is to provide an improved methodand apparatus for handling mill stock -of" rubber or a rubber-likecomposition, conditioning the same for molding and molding the samefoeiore a. can form thereon, to produce homogeneous molded parts. Afurther object .is-to provide a method and apparatus or this type'whichis capable of operating .at-a high rate of production.- It is also anobject to treat mill stock and forming molded articles therefrom in suchmanner as-to minimize stockknitting trouble, to prevent contamina- 1tion of the-stockby air and foreign material and to eliminate airbubbles.-

Another object of this invention is to provide a molding machine bymeans of which-the material to molded may be dispensed to the molds inmeasured quantities. A further object is to discharge from a dispensingdevice to a -temporary holder a-sufiicient quantity of material to form"a charge for a single'mold, and then forcinlg such charge-from a holderinto the mold. It is also an object to provide means for removing fromthe holder any material left after charging the mold, so that a completefresh charge may again he admitted to the holder from the dispensingdevice.

It is also an object of this invention toprovide improved means wherebya charge holder may be moved into and held in charge receiving positionrelatively to the dispensing device for the material. A further objectis to provide carrying means for moving the charge holders from thedispensing device into operative rela tion to a mold.

It is also an object to provide a. machine of this kind with moldhousings of improved constr-uction having removable molds or dies, sothat the mold housings can readily be adapted for producing differenttypes of molded articles. A vfurther object to provide improved meansfor securely holdimg the parts of the mold in correct relation to eachother during molding. A fur- -,,,ther object is to provide mold housingswhich can he supplied with means for heating the molds whenloperating onmaterials which require heat for curing the same after molding. Anotherob- 'ject is to provide a mold housing with means of improvedconstruction for securely clamping the 3'5 Glaims. ('01. 18-30;)

two parts of the mold housing together and for readily separating thesame-for removal of the molded articles.

Another object is to provide mechanism of improved construction by meansof which the two parts of a mold canv be firmly clamped together withhigh pressure during the molding operaation. v

Another object is to provide mechanism of improved cons-tructioh formoving a turret on which the molds are mounted and the carrying meansfor the charge holder's so as to move these parts into operativerelation to each other for molding. A further object is to provide meansof improved construction for locking the turret and the chargeholder-carrying member in cor- "rect' relation toeach other for eachmolding operation. 1

Other obiects-and advantages of this inven- "tion'will appear from thefollowing description and claims.

- In the accompanying drawings:

Fig. l is an elevation of a molding machine embodying this invention,

Fig. 2 is a top plan view thereof.

Fig. '3 is a fragmentary sectional plan view thereof, on an enlargedscale.

Fig. 4 is a fragmentary elevation, partly in section, on line -fl' l,Fig. 3.

Fig. 5 is a fragmentary elevation of a part thereo-flooking in thedirection of the arrows on line 5- 5, Fig. 3. I

' Fig. 6 is a fragmentar elevation thereof,

1 shorwlng the mechanism for exerting pressure on the mold to preventseparation of the parts thereof during the molding operation. Figure; '7is a similarelevation, partly in section, land-showing the parts indiilerent positions.

Fig. 8 a sectional elevation thereof, on line 8-8, Fig. 7.

Fig. 9 is a side elevation of a mold housing embodying our invention. v

Fig. 10 is a fragmentary elevation of the mold housing shown in Fig. '9,partly inv section, and showing the upper part of the mold housing inraised position.

Fig. 11 is a plan view thereof, partly in section, on line 1 1-41, Fig.9.

Fig. 12 airagmentary elevation of the machine, partly in section onlin'e l-'2-I'2, Fig. 3.

Fig. 13 a: fragmentary section of the machine, takenon line iii-43, Fig.1,

Fig. 14 is a plan'view, partly diagrammatic and showing the connectionsfor supplying actuating fluid to the cylinders of the machine.

I a pair of upright tension members 3|.

The frame or stand on which the parts of the machine are mounted may beof any suitable construction, that shown including a base plate l5having two upright columns or pillars l6 secured thereto and an uprightcolumn I! which may, for example, be of I or H-shaped cross section. Thetwo pillars I6 and the pillar I! have a pair of horizontal upper framemembers l8 and I9 rigidly secured to the upper ends thereof. The flangesmay be removed from the upper end of the column I! so that the webportion projects upwardly between the two upper horizontal frame membersIt and I9 which may be welded or otherwise secured to the web portion20, and adjacent parts of the column II. The upper ends of the pillarsl6, which may be of rectangular cross section, may be slightly notchedto receive the upper frame members [8 and I9, which are offset so thatthe portions secured to the columns I6 are'spaced farther from eachother than the ends thereof which are secured to the web of the columnH. The horizontal frame members l8 and I9 project beyond the columns I6and terminate at a cross beam 2| extending crosswise of the machine andare rigidly secured thereto, for example, by weld-' The machine includesa turntable or turret 22 on which the molds are mounted, the turretbeing journalled to rotate about a pillar or column 23 which alsoextends upwardly from the base I5, and if desired, posts 24 may beprovided for forming additional supports for the turret. These posts mayhave rollers 25 suitably journalled between a pair of plates 26 securedto the upper ends of the posts 24 and on which the lower face of theturret may bear. When a mold on a turret reaches the injection position,the two parts of the mold are clamped together to resist separation ofthe two parts of the mold during the injection, this clamping beingeffected by downward pressure exerted on the upper half of the mold. Inorder to resist this downward pressure exerted on the mold at theinjection position, an anvil or support '21 is provided, the anvil beingsupported on a pair of plates or beams 28, one end of each of which issecured to one of the pillars l6 and the other end of which is securedto the column 23 on which the turntable is journalled. Since a heavypressure is exerted against the mold which is in the injection position,which pressure reacts against the horizontal frame members l8 and IS,the frame of the machine is preferably further reinforced, and this, inthe construction shown, is

' accomplished by providing a structural connection between the upperframe members l8 and I9 and.

the lower plates or beams 28 on which the anvil rests. This connectionmay, for example, include a lower transverse beam 30 arranged below theplates or beams 28, and on which these plates rest, the beam 30 beingsubstantially of the same.

length as the upper cross beam 2| and the outer ends of the two beams 2|and 30 are connected by These tension members may be notched to receivethe ends of the beams 2| and 30 and these beams may also be welded tothe tension members, thus forming a rectangle or closed loop whichserves to limit displacement of the upper frame members l8 and I9relatively to the anvil supporting plates 28. The upper face ofthe'anvil is preferably flat and forms a bearing surface on which theunderface of the turret is supported so that the turret in its rotarymotion slides on the upper face of the anvil to bring successive moldsinto injection position over the anvil. q,

The molds or dies are located in housings designated as 33 which areadvanced with the turret on which they are supported so that they arepositioned one at a time over the anvil 21,

5 the upper surface of the anvil being formed to provide a bearing forthe undersurface of the turret or turntable 22. During. the injection ofplastic material. underhea'vy pressure, this pressure will tend toseparate the upper and lower 10 parts of the mold and suitable clampingmeans are, therefore, provided to prevent such separation of the partsof the mold. In the construction shown for this purpose, we haveprovided a platen 34, see particularly Figs. 1, 6 to 8, which may be 5pressed against the upper surface of the mold housing so that the platenpresses the two parts of the mold housing together and also presses themold housing and a portion of the turntable or turret 23 against theanvil 21. This platen may 20 be movably mounted in any suitable manner,and

in the construction illustrated, we provide brackets 35, which arewelded or otherwise rigidly secured to the outer sides of the uprightframe members IS. The outer ends of these brackets 35 are apertured orotherwise suitably formed to receive vertical guide. pins 36havingcylindrical portions which fit into holes formed on outwardlyextending lugs or wings 31 ofthe platen, so as to permit movement of theplaten from a mold disengaging position, shown in Fig. 6, to a mold haveshown a combination of a hydraulic cylinder and cams which-multiply thepower of the cylinder so that the platen will be urged against the moldwith a very high pressure. In the constructionillustrated, we haveprovided a cylinder 40 40 which is mountedon the upper face of theplaten 34 and which isheld in place on the platen by means of aplurality. of bolts 4 The platen is provided with a passage 42-.formotive fluid, connecting with the lower end of .the cylinder 40, and theupper end of the cylinder is provided with a passage 43 for admittingfluid under pressure to the upper portion of the cylinder. The cylindercontains a, piston of any usual construction to which apistonrod 45 issecured.

In order to multiply the pressure exerted on the piston by the fluidadmitted into the passages 42 or 43, we have provided a cam mechanismwhich includes a movable cam member 41-which is guided for verticalmovement by means of an upwardly extending projection or stem 48 whichextends betweentwocross bars 49 and 50, the upper portions of whichare'rigidly secured to the lower faces of the horizontal frame membersI8 and IS. The cross bar 49 is arranged dil rectly below the'transverseframe member 2|, and if desired, this frame member may be recessed toreceivean upwardly extending projection 5| of the cross bar 49. Asimilar upward projection of the cross bar 50 extends between (,5- thehorizontal upper framev members I3 andv IQ for more securely securingthe cross bar in place. The innersurfaces of these cross bars guidethestem 48 of the movable cam 41 and preferably a pair of rollers 53,arearranged between the two crossbars and pivoted onbearing pins 54extending through the cross bars, these rollers engaging theopposite'sides of the stem 48 of the movable cam. 7 g

The movable cam is providedat oppositev sides thereof withhook -shapedportions 56 which have curved recesses 5'! formed therein, the recessesextending upwardly and toward each other. These cam recesses cooperatewith rollers 58, each suitably journalled on a shaft 59. Both ends ofeach shaft have a pair of pressure links 66 connected therewith, seeparticularly Fig. 8. The lower ends of each pair of links are secured toa shaft 6 I. The two shafts 6i bear in arc-shaped recesses 52 formed inthe upper surface of the platen 3 3.

Each of the upper two shafts 59 has a pair of rollers 64 suitablyjournalled thereon, and these rollers, which are arranged at oppositesides of the cam-actuated rollers 58, bear on stationary cams .65, whichare suitably secured on the lower surfaces of the cross bars 49 and 50.These cams are of less thickness at the middle portion thereof than atthe opposite ends thereof, and consequently, it will be obvious that ifthe upper ends of the pressure links Eli are swung outwardly, therollers 64 will roll on the downwardly inclined portions of the cams 65and thus cause the rollers and the, pressure links 68 to move downwardlyand to move the platen 34 downwardly. It will also be obvious that whencompressed fluid is admitted into the lower end of the cylinder it, thusforcing the piston rod @5 upwardly from the position shown in Fig. 7,the cams 5! will cause the upper ends of the pressure links 60 to swingfrom positions in which the rollers 64 engage the middle portions of thecams 85 as shown in Fig. 6, into positions in which the rollers engagethe outer portions of the cams as shown in Fig. '7, thus in turnproducing downward movement of the platen 34. By means of the camsdescribed, the downward pressure exerted by the platen is many timesthat of the pressure exerted by the piston rod 45, and furthermore, theplaten will be rigidly held in its lower position in such a manner thatupward pressure of the upper portion of a mold housing 33, as wouldoccur during the injection of plastic material into the mold, would notexert any substantial downward pressure on the piston rod 45, for thereason that the pressure links 66 extend nearly at a right angle to theinclined surfaces of the cams when the parts are in the position shownin Fig. '7.

Suitable means are also provided for supporting the platen 34 in anupper position clear of the molds 33 when the clamping pressure on themolds is not required, so that the molds may be passed by the turretinto a position between the anvil and the platen. In the constructionshown for this purpose, means are provided for limiting the extent towhich the movable cam may be lowered, so that fluid pressure acting onthe upper face of the piston in the cylinder 40 will tend to raise theplaten. Any suitable means may be employed for this purpose, and in theconstruction shown, the two arms of the movable cam are provided neartheir outer portions with shoulders 61, and suitable stationary stopsare provided with which the shoulder portions may engage for limitingdownward movement of the movable cam. In the construction shown for thispurpose, a pair of angle bars 68 are provided at each end of the movablecam, the angle bars being secured at their upper ends to the cross bars49 and 5B and having cross pieces 69 secured to the lower ends thereofin position to be engaged by the stop shoulders 6'! on the movable cam.Consequently, when fluid'under pressure is admitted to the upper inlet43 of the cylinder and presses downwardly on the upper face of thepiston, the movable cam 41 is moved downwardly to move the upper ends ofthe pressure links 60 toward each other, and thereupon the shoulders 61willengage the stop members 39 so that the movable camv will besupported or hung from the stop members, as shown in Fig. 6. Fartherdownward movement of the piston of the cylinder will, consequently, beprevented and the fluid pressure will act on the upper cylinder head toraise the cylinder 40, and thus cause the platen 34 to be raised clearof the mold 33.

It will be noted that when the pressure is applied to the mold, thereaction between the various forces is mainly absorbed by therectangular pressure resisting frame or closed loop which has been.described, and which includes the two upright tension members 3i and thetransverse plates or beams 30 and very little of these forces aretransmitted to other parts of the frame of the molding machine. Theclamping of the mold by means of the construction described serves notonly the purpose of preventing the seperation of the two parts of themold, but also holds the mold firmlyagainst movement when the injectionnozzle is pressed against the mold about the opening therein, thuspreventing the transmission of any horizontal pressures as a result ofthe injection, to the turntable and to the upright column 23 on whichthe turntable is supported.

The mechanism thus far described may be used in connection with anydesired molding material, and the injection of material into the moldsmay be accomplished by any suitable or desired means. We have, however,herein illustrated suitable means by which the machine is enabled tooperate in connection with the molding of rubher or rubber-likematerials. The term rubber is herein employed to include not onlynatural rubber, but also any rubber-like materials which arethermo-setting or which can be vulcanized by heat. Satisfactory moldingof rubber articles involves the difi'lculty that if the rubber prior tomolding is out in small pieces which are fed to the apparatus, thesepieces when exposed to air, dust, and the like, rapidly have filmsformed on their surfaces which prevent the producing of molded articlesin which all parts of the articles are homogeneously bonded together. Inother words, if a portion of rubber having a film thereon enters themold, the adjacent particles or rubber do not adhere properly to thefilm, thus forming weak places in the molded articles.

In order to accomplish this desired result, We provide on a machine anapparatus for thoroughly mixing and plasticizing the material, and thentransferring or extruding measured charges or quantities of the materialto a charge holder, by means of which the charge of material is carriedto the injection position for injection into the mold. Any suitable ordesired apparatus may be employed for thoroughly mixing and extrudingthe stock, and in the construction illustrated, we have shown anextruding apparatus having a housing 12 having a cylindrical bore inwhich a worm 13 operates, see particularly Fig. 2, the housing having areceiving opening 74 into which milled stock of rubber may be fed orinto which a milled stock may be automatically drawn by rotation of theworm 13. The worm is turned in any suitable manner by means of a motor15 connected by means of a transmission chain covered by a guard 16, orother suitable transmission means to the worm shaft. This apparatus iswell :known in the art, and is similar to apparatus used for extrudingrubber, for example, for forming rubber tubing and is, therefore, notherein described in detail. The worm forces the rubber through adischarge orifice 11, Fig. 12, into a nipple or nozzle 18 of a holder,when the holder is moved to the left in Fig. 12, so that the nipple.

enters the outer part of the discharge orifice I! of the extrudingapparatus.

Material to be injected into a mold is carried from the extrudingapparatus to a mold by means of a charge holder. In the constructionshown for this purpose, a plurality of holders for carrying charges ofthe material to be molded from the extruding apparatus 12 into' positionto be injected into a mold are mounted on a movable member so that theycan he moved back and forth between the extruding apparatus'and themolds, and in the particular construction shown, four of these chargeholders are provided and are mounted on four arms of a spider 80 whichis rotatably mounted on the machine in any suitable manner. For example,the machine may include an angularly arranged frame comprising a pair ofupright frame members 8| which may, for example, be in the form of Ibeams, the lower ends of which are rigidly secured to the base l5, seeFigs. 1, 2 and 3. The upper ends of these upright frame members areconnected by means of a horizontal member 82 which as shown is also inthe form of an I beam which may also be secured to the lower surfaces ofthe upper horizontal frame members l8 and i9 for further reinforcing thesame and for holding the auxiliary frame member in fixed relation toother parts of the machine. One of the upright columns 81 has a bearingmember 83 rigidly secured thereto in any suitable manner. For example,the bearing member 83 may have a. base 84 which is welded or otherwisesecured to one of the upright columns 8!. The spider 86 has its hubportion journalled on the bearing member 83, and is held againstmovement lengthwise of the bearing pin in one direction by a shoulderformed on the bearing member, and in the other direction, by means of adisk or washer 85 secured to the outer end of the bearing pin by meansof a screw 86, see particularly Fig. 3. Any other means for rotatablymounting the spider 80 may be employed.

The charge holders for the plastic material may be secured to the endsof the arms of the spider in any suitable or desired manner, and in theconstruction illustrated, the ends of the arms are provided with webs orpads 88 which extend at an angle to the axis of the spider, and theouter surfaces of which are preferably flat and are formed to receivefiat bases 89 of cylindrical guide members or sleeves SE} for thechargeholders 9!. The guide members 99 have portionsof their cylindricalperipheries cut away, asclearly'shown in Figs. 1 and 3, to renderportions of the charge holders accessible, and the charge holders aremovable axially to a limited extent relatively to their guide sleeves.

Each holder comprises a cylindrical shell por tion Q2 of such diameteras to fit in the cylindrical holder guide 90 and to slide therein and;an end portion 93 of rectangular form, the rectangular part beingsmaller in diameter in one direction than the diameter'ofthe cylindricalpart thereof, while in a direction at a right angle thereto, therectangular part is approximately equal to the diameter of thecylindrical part, so that the corners of the rectangular part act asstops to limit the extent tov which the charge holder may move in itsguide toward the axis of the spider, as may be clearly seenin Rig-.5.The;

rectangular part of each charge holder terminates in the dischargenozzle 18 of the holder.

Each charge holder is provided with a central cylindrical aperture ofsubstantially uniform diameter throughout the greater portion of itslength, but which terminates in an aperture of materially smallerdiameter in the nozzle 18, and a plunger 94 is slidably arranged in thecentral aperture of the charge holder for forcing the chargeof materialout of the holder into the mold. The plunger 94 preferably has adiskshaped portion 95 in the outer end thereof which fits within thecylindrical bore of the holder guide and acts as a crosshead to keep theplunger 94 in alignment with the bore in the holder. The disk 95 alsohas a portion 96 of reduced diameter which may be engaged by a movablepart to force the plunger 94 lengthwise of the aperture in the holder.Preferably a stop 91 is provided on the end of the holder guide by meansof an inturned portion or flange thereof, see Fig. 3, for the purpose oflimiting the return movement of the plunger 94 in the guide when theholder is being filled with a charge of material to be molded. Thus itwill be noted that the rectangular part of the charge holder limitsits'movement relatively to the guide, and the stop flange 9'! limits themovement of the plunger out of the charge holder, the two stopscooperating to determine the capacity of the charge holder. Any othermeans for limiting the movement of these parts may be provided, ifdesired.

Means are also provided for urging the charge holders yieldingly intotheir innermost positions toward the axis of the spider on which theyare mounted, so that b rotation of the spider, the holders can easily bemoved one at a time into axial alignment with the inlet orifice of amold and can then be moved lengthwise of their holder guides to fit thedischarge nozzles 18 of the charge holders into the charge receivingapertures of the molds.

Any suitable means may be employed for this purpose, and in theconstruction illustrated, we have provided at a side of each holderguide a projecting part or shelf 99 which forms an additional guide forthe charge holder in its movement in the holder guide 90 in that oneface of the rectangular portion 93'of the holder may slide on thisshelf. The shelf, consequently, also prevents rotation of the chargeholder in its guide.

' The shelf further serves as a support for a spring,

and in the construction shown for this purpose, the shelf is providedwith an outwardly extending web or lug Hi0 having an aperture thereinthrough which a pin [0| extends. The opposite ends of the pin serve tosupport two coils 12 of U-shaped spring, see particularly Figs. 3, 5 and12, the spring having a U-shaped portion I03. The ends of the springsbeyond the coils are Supported by means of a pin I84 secured in a holein the web or lug I00 and extending outwardly from opposite sidesthereof. This pin places the coils of the springs under tension in a'manner to urge the U-shaped portion I03 of the spring against thecharge holder.

In the particular construction shown, each charge holder is alsoprovided with a pair of wheels rotatably mounted on bearing pins HE'Ssecured to opposite sides of the rectangular part of the holder, and thesides of the U-shaped portions of the springs in the particularconstruction shown engage these pins I06, and thus urge the chargeholder into its guide, until the corners of the rectangular portionthereof engage the end of'the :holder guide. It will be noted that thesprings alone hold the charge holders against outward movement in theirguides and by flexing a spring out of engagement with its charge holder,the charge holder can be readily removed radially of the spider and canbe quickly replaced by another charge holder. Consequently, chargeholders can be readily cleaned or repaired without shutting down themachine. g

Means are provided for drawing each charge holder as it arrives'at thechargereceiving station into engagement with the discharge portion ofthe extruding apparatus I2, for injecting' material into the chargeholder. In the construction shown for this purpose, Figs. 2, 3 and 12,there is mounted on the extruder a pair of levers I II] which have thelower portion I I I thereof offset and extending toward each other andformed to engage the wheels or rollers I05 of each charge holder as itmoves between the levers into charge-receiving position 'at the extruderI2. These levers may be pivotally mounted in any suitable manner, forexample, on brackets II2 suitably secured to the extruder, for example,by means of posts II'4 secured to the extruder and to the ends of whichthe brackets are fastened by means of screws. The levers are pivoted tothe brackets II2 on suitable bolts or pins H3. The other ends'of thelevers may be connected with any suitable power 'device for swinging thelevers so that the lower end portions I I I thereof, by engaging therollers I05, will move the charge holders SI into engagement "with theextruder I2 so that the nozzles I8 thereof may be tightly pressed intooperative relation to the discharge orifice ll of the extruder. In theconstruction shown for this purpose, we have provided a cyl-' inder H5which may also be mounted on the extruder and which has a piston I I6therein connected by means of a piston rod I I"! to the upper ends ofthe two levers, for example, by means of a yoke I IB, Fig. 2. From theforegoing description, it will be obvious that when fluid pressure, suchfor example as compressed air, is admitted into'the cylinder H5 throughthe pipe I20, the piston IIB will be moved against a return spring I2Iin a direction to the right Fig. 12, thus swinging the levers H5 in aclockwise direction and drawing the inwardly extending endi'portions IIIof the levers to the left against'the rollers I05, which results inmoving the chargeholder 5I' to the left so that the nozzle I8'thereofenters; into the discharge aperture 'I'I o f the extruderJ The swingingof the levers I It! also causes the motor 75 of theextruderjlto'bejoperated momentarily' to discharge material from theextruder into the charge holder. This may, for example, be accomplishedby means or a switch or motor starter I24, which, in the constructionshown, is mounted on top of the cylinder I05. This switch or starter hasa push button or plunger I25, Fig. 12, which is normally urged outwardlyinto circuit closing or motor starting position, and is held againstoutward movement by an upwardly projecting arm I secured to the yoke II8. When the parts are in the position shown in Fig. 12, the operationof the motor is interrupted because the plunger I25 is pressedinwardlyby the arm I25. However, when the piston II6 moves the yoke H3to the right in Fig; 12, the plunger I25 moves outwardly into motorstarting position.

The quantity of materialwhich is fed to the charge holdersmay becontrolled by means of a limit switch I21 having a lever IZ'IajFig. 3,

10 the -end of which is arranged in the path of move ment of a part ofthe plunger 94, for example, the disk 95. This switch may be in thecircuit of the eXtruder motor 15 and is normally closed by suitablespring means but is moved into open position by the actuation of thelever I2'Id by This switch may be otherwise con-- the plunger. nected tostop the motor when the switch lever I2Ia is actuated by the plunger.The switch I21 may be adjustably mounted on a suitable bracket I2'Ib,which may, for example, be secured to the frame member II. By properlocation 'of the switch member on the bracket,the quantity of materialextruded into each charge holder may be controlled as may be required bythe cavities in the molds. v v The spider on which the charge holdersfor the material are mounted is advanced so th'at'th'e' charge holderwhich has just been filled is moved away from the extruder and an emptyholder moves into position to receive a charge of material from theextruder. At the same time, one

of the charge holders which has been filled is moved opposite the chargereceiving opening in a mold on the turntable 22, thus occupying theposition shown in Fig. 3. When this movement of the spider is completed,the piston 9d of the charge'holder is pressed into the bore of'th'eholder for discharging the charge from the will move toward the moldagainst the action of the spring I03 because of the friction between thematerial and the walls of the holder, this" friction being sufficient tocause the piston il i'to move the charge holder into a position in'whichthe discharge nozzle I8 thereof registers with the receiving opening inthe mold, whereupon farther movement of the piston 94 forces the chargefrom the charge holder into'the mold to an extent necessary to fill theentire mold cavity completely. During this operation, the charge holderwill be pressed against'the mold with's'ufficient force, due to thefriction between the charge and the wall of the charge holder, to ensurethe charge entering the mold cavity.

Upon completing of the molding operation; the

piston in the cylinder I28 is moved in the reverse direction, but thepiston 94 will remain in the charge holder 91, and the holder togetherwith the piston 94 will be moved back into the charge holder guide bythe spring I03. The charge holder will then again be in the positionshown in Fig. 3, but the piston 94 will be in the same.

relative position in the charge holder which it occupied at thetermination of the molding op-l so that all of the material when finallyinjected into the mold will be homogeneous and will bond or knittogether so that no weak places will be found in the molded articles.Also the charges of material fed to the charge holders will be protectedfrom contact with air, dust, or the like, so that no films or coatingswill be formed on the charges. The extruder also heats the materialbecause of the Working of the same by the spiral or feed screw I3 of theextruder, thus rendering the material more plastic and ready formolding, thus facilitating the forcing of the same into the chargeholder and the injection of the same into the mold cavity.

When the machine is used in connection with the molding of rubber orrubber-like materials, it may at times be necessary or desirable aftereach molding operation of the machine to remove from the charge holderany material remaining therein, and for this purpose, each charge holdermoves from the molding position to another position in which theremaining material may be removed from the charge holder, this being thelower position of the holder, as shown in Fig. 1. When in this position,the disk or crosshead 95 of the charge holder piston 94 is located inoperative relation to the end of a lever I32, one end of which may bepivoted on the upright frame member 8 I. Another cylinder I33 is mountedon the upright frame member 8|, preferably by means of a pivotalconnection I34, and the piston rod of this cylinder is pivotallyconnected by means of a clevis I35 to the lever I32. When motive fluidis admitted to the cylinder I33 to the upper side of the piston therein,the piston will move the clevis downwardly and also swing the lever I32downwardly so that the outer end thereof presses against'the disk orcrosshead 95 of the charge holder piston 94 and forces this piston tothe lower end of the bore in the holder, and at the same time, moves thecharge holder downwardly against the action of the holder return springI03.

Below the charge holder while in this position, is arranged a device forremoving material from the opening in the discharge nozzle of the chargeholder when the holder piston 94 has moved to the limit of its stroke inthe charge holder, this device including a stripper ring support I36,Figs. 1 and 13, which is provided with an aperture formed to receive thedischarge nozzlel'lfi of the holder, this stripper ring being mounted ona suitable auxiliary frame including a member I31 which is inclined soas to be substantially perpendicular to the axis of the charge holderwhen in strippin position, and which is secured in any.

suitable manner, for example, at one end thereof, to one of the uprightframe members 8! and at its other end to a post I38 extending upwardlyfrom and secured to the base I of the machine. This frame member I3? isprovided under the stripper ring support I36 with an aperture I39through which the excess material may drop, for example, into areceptacle I40 underneath the discharge aperture. The stripper ringsupport I36 is provided on its underfaoe with a circular opening orrecess in which is secured a stripper ring I4I having a series ofopenings or apertures therein through which the left-over material I42may be fonced as clearly shown in Fig. 13, and in its upper face, thestripper ring support has a tapered hole into which the dischargenozzles of the charge holders may enter when the charge holder is movedtoward the stripper. The middle or hub portion of the stripper ring hasa 12 suitable projection mounted thereon which extends into thedischarge aperture in the nozzle I8 of the charge holder to removeexcess material therefrom, and this projection may be of any suitablekind, and in the construction shown, is of spiral configurationsomewhatsimilar to an auger as shown at I44, the stem I45 of which is mounted inthe hub-portion of the stripper ring so that the spiral or anger portionwill extend into the discharge aperture of the charge holder when thesame is moved in its guide toward the stripper. This projection or augermember is held stationary and as the piston 94 of the holder moves tothe end of the cylindrical bore in the charge holder, it forces materialin the charge holder into and through the discharge orifice.

The material in the discharge orifice will flow around the spiral orauger bit, and consequently, when the charge holder is moved upwardlyout of the position shown in Fig. 13, upon reversal of the pressure inthe cylinder I33, which causes the lever I32 to move upwardly in Fig. 1,the return spring I03 will -move the charge holder away from thestripper ring and cause the'material remaining in the discharge orificeof the charge holder to adhere to the auger bit as the holder is movedaway from the stripper ring, thus clearing the material out of thedischarge orifice of the holder. Any other means may be provided forremoving the remainder of the charge of material from. the holder, or ifthe machine is operated on a material which does does require removal ofthe remaining material,- this mechanism for removing the remainingmaterial may, of course, be omitted.

Means of any suitable construction may be provided for advancing theturntable 22 and the spider so as to bring the successive molds intocorrect position relatively to the holders on the spider and forbringing these holders on the spider into positions to receive a charge,to deliver the charge to the mold and to permit the remainder ofmaterial to be removed therefrom. In the construction shown for thispurpose, see particularly Figs. 1-to4, the advancing mechanism isactuated by means of a pistonarranged in a cylinder I50, the pistonhaving a piston rod I5I which is connected to an outwardly extendingpart or arm I52 rigidly secured on a slide I53. This slide in theparticular construction shown is mounted to slide on a side of the anvil21, for example, in a groove or slot formed in the side of the anvil inwhich the slide I53 may reciprocate, and in whichit may be confined byflanges or parts I54 of the anvil which overhang the slot therein inwhich therslide I53 reciprocates, see Fig. 4. One end of the slide has alink I55 pivotally connected therewith, the other end of the link beingconnectedto a pawl arm I56, one end of which is secured to a sleeve I51which is mounted to oscillate about the bearing pillar 23 on which theturret .or turntable 22 is rotatably mounted. I59 represents a ratchetring which is suitably secured to the lower face of the turret 22, andwhich has ratchet teeth I60, with which a pawl I6I pivoted on the endportion of the pawl arm I56 may engage. One end of the pawl has a springI62 secured thereto for urging the other end of the pawl into engagementwith the ratchet wheel I59.- The movement of the slide 53 in theconstruction shown is such that at each reciprocation thereof, theturret is advancedto a distance equal to the distance between adjacentratchet teeth I60. V

The other end of the slide I53 is suitably conaerasoa nected to produceintermittent rotary motion of the spider for advancing the same step bystep. In the particular construction shown for this purpose, the slideI53 has an upwardly extend ing arm I55 and which is rigidly secured tothe slide. At one side of this upwardly extending arm, a connecting rodIE6 is pivotally mounted, and the other end of the connecting rod ispivotally secured to a pawl lever I61 which is rotatably mounted on aportion of the bearing stud 83 on which the spider is rotatably mounted.The other end of this pawl lever has a pawl Hi8 pivotally mountedthereon, the pawl in this construction being formed to engage with theteeth of a ratchet wheel I10 which is secured to the hub portion of thespider 80, the dogs dropping by gravity into engagement with the teethI1! of" the ratchet wheel I10. Consequently, by reciprocation of theslide I53, the pawl lever I61 will be moved from the position shown inbroken lines in Fig. 4 to the full line position, thus advancing thespider through a quarter of a revolution, the spider in the particularconstruction shown having four arms carrying the four charge holders forthe material. Consequently, movement in one direction of the slide I53will simultaneously advance the turret 22 and also the spider 80 so thata mold to be charged and a charged holder containing a charge aresimultaneously brought into operative relation to each other.

Means are also provided for locking the turret and the spider when inoperative relation to each other, and the locking means are' preferablyalso formed to position the spider and turret relatively to each othermore accurately than can be done by means of the ratchet mechanism-sonly. For this purpose, the turret is provided with a latch member I foreach position of the turret and the anvil 21 is provided with a suitablerecess inwhich a locking dog I16 is slidably arranged, see particularlyFig. 3 The outer end of the dog is accurately formed to fit into anaccurately formed notch or recess I11 ineach of the latches I15 of theturret. The locking dog is mounted on a stem about which a coil spring{18 is arranged, one end of the coil spring bearing against the end ofthe locking dog I16 and the other end bearing against the base of aguide bracket I19, which base is rigidly secured to a side of the anvil21, and has a leg or web extending from the base toward the middleportion of theturret. The pin, to one end of which the locking dog it?'is secured, has a head I89 formed on the other urges the dog I16 intoengagement in the recess I11'of any of the latches I15, andconsequently, serves to lock the turret in fixed position and alsoaccurately position the turret so that a mold mounted thereon will beaccurately located with referenceto a charge holder SI.

Means are also provided for moving this locking dog l16'out of itslocking position, to permit advancing the turret. For this purpose, theslide 53 is provided with ashoulder I83 formed on the upper surfacethereof. The roller E32 and the shoulder I83 are so located relativelyto each other that during the movement of the slide I53 to the left inFig. 3, the shoulder I83 contacts the roller I82, resulting in movementto the left in Fig. 3 of the roller I82 and the locking dog I16connected therewith, thus withdrawing the locking dog from the latch I15during the latter part of the movement of the slide. After the slide hasmoved to the limit of its movement to the left in Fig. 3, thus causingthe latch I35 to engage another tooth I63 of the turret ratchet wheelI59, the slide I53 moves back in the opposite direction, thus impartingmovement to the turret while the dog I16 is held out of engagement witha latch. After initial movement of the turret by the slide, at leastsufficient to move the latch I15 out of the path of the locking dog, theshoulder I83 of the slide moves out of engagement with the roller I82,thus permitting the dog to be again moved outwardly by the spring I18and when the next latch I15 approaches. the dog I16, the curved or camface thereof moves the dog back until the notch or recess "11 in thelatch registers with the dog, whereupon the spring I18 will move the doginto locking position in this latch.

The spider 88 is also provided on each arm thereof with a latch I85,these latches being similar in form to the latches I15 on the turret,and each latch is formed to cooperate with a locking dog I86 which isslidably mounted in a guide or slideway I84 secured on a fixed part ofthe machine, for example, on one of the upright columns I6, see Figs. 3and 4. This locking dog is also pressed by means of a coil spring I81into holding position and the dog is provided with an outwardlyextending arm or projection I88 which extends into the path of movementof the upwardly extending arm I of the slide. Con sequently, during thereturn movement of the slide I53 to place the pawl I68 into engagementwith another toothof the ratchet wheel Ill), the upper portion of theupright arm 5655 will move into engagement with the arm or projectionE38 of the locking dog I86. This arm preferably has a face extendingtransversely of the direction of movement of the slide, so that theupright arm I65 of the slide when in the position shown in broken linesin Fig. 3, will engage the arm I88 of the locking dog and move the sameto the left in Fig. 3, or to the right in Fig. thus disengaging thelocking dog from its-latch H5. During the oppositestroke of the slide,after the spider has been advanced to some extent, the upright arm I65of the slide again releases the locking dog I86 so that the same maymove into engagement with another latch member on the spider. Any othermeans for locking the turret and spider in their operative positions maybe provided, if desired.

The mold housings 33 are shown in Figs. 1 and 2 and more in detail inFigs. 9 to 11 inclusive. Each of these mold housings includes a baseplate I90, see particularly Fig. 2, which rests directly on the turretof the machine. Each of these base plates has an upwardly extendingflange or wall I9I which is preferably formed integral with the baseplate. Each [mold housing is made in two parts, the lower part ISZ whichis secured to the base plate in any suitable manner, and an upper partor top I53 which is hinged to the lower part. The lower part may beprovided with lugs at the inner end thereof, namely, the end nearest tothe center of rotation of the turret, and the upper part of the moldhousing is provided with brackets I which have slots therein throughwhich hinge pins I96 may extend. The lower half of the -mold housing hasa web or horizontal wall having a substantially flat upper surface I97on which the IOIWGI' die or mold I98 may rest, and the upper half ofthemold housing has a corresponding Web or wall with a lower surface I99against which the upper mold or die 200 may bear. The molds or dies maybe heated in any suitable, or desired manner, and in the constructionshown, the mold housings are provided with annular recesses whichterminate at the die supporting webs or walls and in which electricheating elements 202 of annular form may be arranged to be as close aspossible to the fiat Walls or webs of the mold housing halves whichsupport the molds or dies I88 and 28!]. Preferably one of the halves ofthe mold housing is also provided with a hole therein extending from oneend thereof adjacent to the surface which supports the mold or die and athermoresponsive element 203 is arranged in such hole in a position tobe responsive to temperatures of the dies or molds. If a heat-responsiveelement is used containing an expansible fluid, such element may beconnected by means I of a suitable tube 204 with )3. current-controllingdevice 205 mounted on the upstanding part I9I of the base plate I90 ofthe mold housing, see Fig. '2. This device may be provided with anadjustable knob 205 by means of which the temperature to which the moldhousing is heated may be controlled or which may serve to interrupt theflow of current to the mold housing. A pilot light 267 may also beprovided on the upstanding part I9! of the base plate for each moldhousing, which indicates when current is flowing to the heating elementsin the mold housing.

In the construction illustrated, heating elements 222 are provided inboth the upperand lower parts of the mold housings, -current beingsupplied to the heating elements by means of conductors 298 and 209which connect with the current-controlling devices 295. hollow portionof the lower mold housing below the heating element therein whichterminates at the base plate I 96, may be filled with asbestos or othersuitable heat insulating material, and similarly the upper mold housingis provided with a similar annular upwardly opening recess, in the lowerpart of which the heating element of the upper mold housing part isarranged, and the r upper portion of this annular recess may be filledwith heat insulating material. In the ecase'of the upper mold, a coveror closing plate 2"] is provided to close the open space in the uppermold housing. Any other means [for supplying heat to the two parts ofthe mold housing and for regulating the temperatures of the same may beprovided. 4

The dies I98 and 220 ma be removably secured in the adjacent portions ofthe two parts of the mold housing in any suitable or desired manner, sothat the cavities of the two dies or molds will be in accurateregistration with each other. In the construction shown for thispurpose, the lower mold housing is provided at opposite sides thereofwith upwardly extending guide walls 2I2 between which the mold I98 ywillfit acurately, and the inner end of the lower part of the mold housingis provided with an upwardly extending wall or projection having anundercut edge portion 2 I4' into which the beveled end of the lower moldor die I98 may extend. The mold or die may be held in correct relationto the lower mold plate by means of a pair of set screws 2I5 extendingdiagonally with refer- The annular.

wall 2 I2, nd the mold or die may be provided at the outer cornerportions thereof with grooves or slots 2H5 forming edges against whichthe set screws 2I5 may engage. Any other means for securing the lowermold or die to the lower mold housing may be provided. In the case ofthe upper mold housing part, Ia, similar construction is provided, aflange or wall portion being provided with an undercut edge 2I8 againstwhich the beveled inner edge of the die or mold may be pressed, and theupper mold housing may be provided at both sides with downwardlyextending wall portions or flanges 2 I9 between which a die will fitaccur ate1y,and with set screws 22% for securing the upper mold or dieto its mold hous-' ing part.

In addition, the two molds or dies may be provided with posts or pilotpins in one of the molds or dies entering holes in the other mold or dieso as to ensure correct registration of the molds or dies with eachother, these pilot pins and holes not being shown, since they arecommonly used in connection with molds or dies of this type.

Means are also provided for clamping thetwo parts of each mold housingtogether and securing them in clamped position, and for readilyreleasing the mold housing parts from clamped position and swinging theupper mold housing part away from the lower one so that the dies ormolds will be easily accessible for removing molded parts therefrom. Inthe construction shown for this purpose, we have provided a linkmechanism which is hand-operated and which includes a pair of togglelinks 224 and 225 connected by means of a pivot 226. The toggle link 224is pivoted to a lug or projection 22'! on the upper part of the moldhousing, and the lower end of the other toggle link 225 is pivotallymounted at 228 on the lower mold housing part. One set of these togglelinks is preferably provided at each side of the mold housing. S

It will be readily seen that when the toggle links are in the positionshown in Fig. 9, the mold housing parts are securely drawn together andthe three pivots of the toggle links are substantially in alignment orin dead center relation to each other so that the mold parts will belocked in their closed positions. vided with handles 230 by means ofwhich the toggle links can be readily moved into opening and closingpositions. When the toggle links are swung by means of the handles 230into the positions shown in Fig. 10, the upper mold housing half will beswung about its pivotal connection into open position in which both ofthe molds or dies are readily accessible, and the pivotal connectionsbetween the links will again be at or past dead center positions so thatthe upper mold housing part will be securely held in its open position.

It is desirable to provide the toggle mechanisms at each side of eachmold housing with a certain amount of resilience so that slightvariations in the thickness of the dies will not require adjustment ofthe toggle links and so that thetwo parts of the mold housing will beyieldingly pressed together. In the construction shown for this purpose,the lower pivot of the toggle link 225, instead of being mounteddirectly on the lower mold housing part is pivotally connected to oneend of a link 23l, the other end of which is pivotally connected at 232to the lower mold housing part. The link 23I is provided with a centralaperture through which a bolt or screw 233 may The upper links 226 arepro-.

ass, the lower end of this bolt having a threaded connection with alug234 extending outwardly from the lower mold housing part. 235 representsa coil spring which is'arranged between the head of the screw 233 and.the link 23! so as to press this link downwardly. By turning the screw233, the spring 235 may be placed under initial compression to thedesired extent, toadjustthe pressure with which the upper mold housingpart is pressed against the lower. Other means for securing the twoparts of the mold or die together may be employed.

Current may be supplied for heating the mold or die in each of thehousings in any suitable or desired manner, and in the constructionillustrated in Figs. 1 and 2, we have provided collector rings 238mounted on theportion of the stationary pillar 23 which extends abovethe turret 22, these rings being stationarily mounted on the pillar 23and suitably insulated therefrom and from each other and may beconnected to a suitable source of electric current through terminals 239extending upwardly beyond an insulating bushing or cylinder 240 on whichthe collector rings 238 are mounted, see Fig. 2. A post 24! extendsupwardly from the turret 22 to which it is secured and has a pluralityof brush holders 242 mounted thereon, one brush being provided for eachcollector ring. Conductors 243 may connect these brushes to thecurrent-controlling devices 205 mounted on the upwardly extending partsof the base plates'of the mold housings, only one set of theseconductors being shown in Fig. 2, the others being omitted for sake ofclarity. Any other means for conducting electric current or otherheating medium to the mold housings may be provided.

, Means are preferably provided for removably mounting the mold housings,on the'turret in such a manner that they can be readily removed andreplaced in accurate relation to the turret; In the construction shownfor-this purpose, the latches I15 of the turret are each provided withtwo upwardly extending arms or fingers 250 which may be formed integralwith the latches and which extend above the upper surface of the turretand preferably have projections 25! at the upper ends thereof whichextend over the edge of the turret. These projections 25! of the fingersare accurately formed to extend into suitable recesses 252 formed in thelower parts of the mold housings, so that when the mold housings aremoved toward the edge of the turret with the projections 25! enteringthe recesses 252, the lower mold housings will be accurately locatedwith reference to the latches H5. The projections 25! of the fingers, inthe construction shown, are formed to extend over the outer edges'of thebase plates I90 of the mold housings. In the construction shown, onlythe outer edges of the projections 25! engage accurately formedsideportions of the recesses 252 in the lower mold housing 'parts, thusavoiding the necessity of having all of the walls of the recesses 252accurately formed. The inner edges of the arms or fingers engage theouter edge portions of the base plates I90 of the molds, therebylocating the molds in definite relation to the outer edge of the turret22.

e The parts described will hold the lower mold housing parts, in correctrelation to the' turret against displacement in any direction excepttoward the axis of the turret, and consequently, we provide the turret.with upwardly projecting bosses or studs 255 which are formed to engageheat of the molds.

corners of the base plates I90 and portions of the inner ends of thelower mold housing parts. These bosses or studs 255 may be the heads ofpins 255 secured in holes in the turret 22. Each base plate I90 of themold housing is of less width at the part thereof beyond the inner edgeof the 'mold housing than at the mold housing itself, and consequently,this reduction in width forms square corners on the base plates intowhich the studs 255 may fit for holding the mold housings in accuraterelation to the turret. By means of this construction, any mold housingcan be very quickly and easily removed from the turret by simply liftingthe inner end of the mold housing or its base plate I90 so that it isclear of the studs 255, and then sliding the base plate and mold housinginwardly toward the axis of the turret to disengage the fingers 250 andtheir projections 25! whereupon the mold housing can be removed from theturret. Similarly a mold housing may be quickly positioned on theturret. The electrical connections between the brushes 242 and theelectrical devices mounted on the upwardly extending parts of the moldhousing bases are preferably made readily detachable so that the cordsor conductors 243 may be easily detached from the molding housing beforeit is removed from the turret.

In the operation of the molding machine, the mold housings are, ofcourse, closed by means of the toggle mechanisms or other suitableclosing devices before they reach the injection position. When at theinjection position above the anvil 21, the two parts of the moldhousings and the molds or dies contained therein are pressed together bymeans of the mechanism which has been described, for the reason that theinjection pressure is much greater than the pressure that can be exertedby the toggle links to hold the mold parts together. After the injectionhas been completed, this pressure is released and the togglemechanisms-described are then sufficient to hold the mold housingstogether for the purpose of curing or vulcanizing the molded articles bythe After the mold housings have been advanced through a number ofstations beyo'nd the injection station, the housings may be opened byhand and the molded parts removed therefrom, and the molds may becleared of all remnants, ofmaterial that may be left in them,

so as to be ready for the next mold operation, whereupon the upper moldhousing part is again lowered by; means of the toggle mechanism andclamped tightly against the lower mold housing part.

.The cycle of operations of this machine may be controlled automaticallyin any suitable or desired manner, for example, by means of a series ofcompressed air valves which actuate valves controlling the flow ofhydraulic pressure from a pressure pump 255 which maybe driven by anelectric motor 26!, the motor and pump being preferably also mounted ona liquid reservoir 265, which is in turn mounted on the base plate !5 ofthe machine, see Fig. 2. For sake of clarity, we have not shown thevarious valves on the first thirteen figures of the drawings, but haveshown them more or less diagrammatically in Fig. 14, in which liquidunder pressure may be supplied from the pump through a pipe or tube 263,and in which 264 represents a return pipe returning the liquid to thereservoir 265.

The operation of the machine may be controlled by means of compressedair received from 19 leading to a pressure reducing valve 253, if suchtype of valve is required, and from this pressure reducing valve, theair enters a valve 2% haying a handle by means of which the valve may beset into open position either manually or by suitable intermittentlyoperating means (not .Shown) When valve 266 is open, air is suppliedthrough a pipe 2?!) to a pipe 21! through a normally open valve 212 andto relays 2'13 and 21!! and to a diaphragm actuated hydraulic valve 215.This valve is opened by the air pressure to Sup ly liquid under pressureto the cylinder I50, this liquid passing through a pipe 216 to the endof the cylinder to move the piston therein toward the cylinder head, andthus advance the turret and the spider to move a mold and a, chargeholder into operative relation to each other at the in-, jection moldingstation. When the piston of this cylinder l5il completes its intakestroke for advancing the turret and the spider, it will open the relayvalve 274, thus allowing air to enter the top of the diaphragm valve 278to which liquid under pressure from the pump enters through the pipe263. The hydraulic air controlled valve 218 admits liquid under pressurethrough the tube 285 to the inlet connection 42 at the bottom of thecylinder 40, thus forcing the piston therein upwardly and the platen 34downwardly to clamp the two mold housing parts securely together. Whenthis piston reaches the upper end of its travel, it opens the air valve213 and admits air through a pipe 21! to the diaphragm top of an airoperated hydraulic valve 28l, which admits liquid under pressure to thehead of cylinder I28 through pipe 283, thus causing the piston in thiscylinder to force the charge out of a charge holder into the cavity of amold. At the same time, this valve Zl also admits liquid under pressureto the head of the piston !33 to actuate the lever I32 to remove anyremaining charge of material from a charge holder which has just leftthe injection station. The forward motion of the piston or plunger ofthe cylinder lZB closes the air valve 272, which is normally open. Whenthe 1 .3. draulic pressure in the cylinder I28 reaches a predeterminedpoint, such, for example, as aprese sure of 500 pounds per square inch,due to the fact that no more charge from a charge holder can be injectedinto a mold, this pressure is trans.- mitted through pipe 284 to thevalve 266, causing it to be unlatched and moved into position to stop afurther supply of air to the pipe Z10 and to discharge the compressedair from this pipe up to the valve 272, which is still closed.

The discharge of air from the pipe 210 also. re-

leases the air pressure from the diaphragm top of the valve 28 I,causing the pistons in the cylinders 528 and I33 to return to theirinner positions at the heads of the cylinders. When the piston ofcylinder I28 returns to this inner position, it permits the valve 212 toreturn to normal or open position, thus discharging compressed air frompipe 27!, which allows the piston in the cylinder 55 to return to itsnormal position. Thedischarge of air from the pipe 21! also relieves thepressure on the diaphragm valve 215 and releases pressure from the pipe2'36 leading to cylinder I51! and admits liquid under pressure to thepipe 290,, thus causing the piston in cylinder 1 5 3 to move e t left inHa hus tu nin he atch H5! and dog A68 to positions to en age other teethof their ratchet mechanisms, ready to again advance the turret andspider. The cycle of operations may then be repeated.

The cylinder 1 I5 is actuated byair pressure in .1.. part cular eentruetien shewn and sui ..e ele. mean may be pr v ded tor eentml ine he up of mn e sed air to th s cyl nder whencharge held r entersinte oerative r ation te the ex ud n a paratu h eestruetien show b wa i e me,e nine 12! leading t this cylinder may enhee ed te the nine. .2. thr ughwh ch a r pa es t the d a ragm a e 81- I des ed the. iter. l-i5ee i1d beactua ed by iqui un er pr sur it m the iqui va ve a tua e by.theslieehre m el e Z8 and h ch upplies pres sure tothe pistons I28 andI33. ince the various p r s ,f r entrel ne the sequen e of oper t of theart e the meehine all r .commen eenst ue en and ten e urch sed en. hopen m ket and h v h reto e e 'eed' s milar Purposes end the tree of meki e th are n herein sh wn i dete I ma be s ra e o u e p eeutie eryeans t ens re t at h eeere iee f the ex udi ap a at s .w l ne .be i e uted b th val e 11 beie a full cha e of material has. been extruded intoa ehar e b er, F this purpose, w have. show Fi en e etriee iie t d-ai av 295, which lv -m e p ace into the eir e .1% in se ies wit he ermallropen val e 21 The va ve 29 i el e nerm ll eeea but is e ec r cally e eeed w t th ei -eu t'ei he ext uder m e 15, So ha e selenoidor magnet inthe air valve 295 wi c ose this. valve whenever urr nt. i ein sup lied tth meter 1.5- c nse uentlv. t e air P s ure wi be maint ned in he r pean eth e co nect d ther wi h unti eth e the valves'z land 29.5areopened, the valve 2, .12 being nenedhy he p ston in he ni et en.inder 12%, end th le t ical y rated. va e 2 5 be n opened when thesupply of current .tg the extruder ter is in er u ted b o t elimit s t12 and. it eeufee, neees er t ot of ese v ve be sim ne usly o en bet airan b ext u te iemthe P1129 1: 1

An o her mean fo matt g the complete fil ine r-the-el a ee h lder w thhe desi e amoun o mat ial e er th ereta iea :e he. e t der i in er uptema ee iplereae er uit eb m an ma he .empl e ter actua ing t tee ear-tse? the ..e he o er S uen e le the. u e o this. m d hees ees a elee d leeere the a e asi eed to the ie e peeit eafter th mater el has. be n ini eee e e a melee. th damp n pressu e on the meld le se ea the turret thenhe we nt i ect niems xe t suit pr ssure 0. the .iae enal uri th orruleen aine n se- This par icula ly tr in enne en w th bber r u be k matS. e Yi G H ha t ey 19 ne t n t flew u of t e mel a t re iei etien ressue is re ased eftet the m eh u as have een. t e tun re in. eleseei nesit.er-

e f e a len th f. time e e er ite-si t e mel e r -1 which may be afterthey have been moved by the turret halfway or more about the axis of theturret, they are opened manually by the. operator by means of thehandles 2.3.0 at opposite sides of the mold housing and the moldedarticles are then removed. f om th molds r e and t e m lds or dies arealso. cleaned to remove any remaining 21 material therefrom. The uppermold housing part is then moved into closed position by means of thelink mechanism described and the mold is then ready for anotherinjection.

When it is desired to change the dies or molds, for producing articlesof a different kind, it is merely necessary to remove the mold or dieplates from the mold housing and replace them with other die plates, andthis may be done without removing the mold housings from the turret. Ifdesired, however, the mold housing may readily be removed by firstbreaking the electrical connections to the heating elements of the moldand then lifting the inner ends of the mold housings to clear the stopsor plugs 255, and then moving the mold housings toward the axis of theturret to clear the projecting fingers 25!, whereupon the mold housingmay be lifted from the turret and replaced by another mold housing.

If for any reason any of the charge holders do not operate properly, forexample, due to damage to the same or due to sticking of the plungers,they can readily be removed outwardly from their guides by merelybending the springs I83 out of the way, and the charge holder canimmediately be replaced by a spare charge holder. In this manner, chargeholders of different capacities may also be easily applied to thespider.

We claim as our invention:

1. In a machine for injection molding plastic materials, the combinationof a frame, a mold supported on said frame, an extruding apparatus fordischarging plastic material to be molded, a charge holder for receivinga charge of material from said extruding apparatus and including acylinder Which receives said change and a piston in said cylinder,mechanism for moving said charge holder back and forth into positionsadjacent to said extruding apparatus and to said mold, separatemechanism actuated when a charge holder is adjacent to said extrudingap-' paratus for pressing said [charge holder against said extrudingapparatus to receive a charge of material therefrom and releasing saidcharge holder for movement to said mold, and a pressure member whichforces said piston into said cylinder to eject material from said chargeholder and inject the same into said molder when said charge holder isin operative relation to said mold.

2. In a machine for injection molding plastic materials, the combinationof a frame, a mold supported on said frame, an extruding apparatus fordischarging plastic material to be molded, a charge holder for receivinga charge of material from said extruding apparatus and including acylinder which receives said charge and a piston in said cylinder,mechanism for moving said charge holderback and forth into positionsadjacent to said extruding apparatus and to said mold, separatemechanism actuated when a charge holder is adjacent to said extrudingapparatus for pressing said charge holder against said extrudingapparatus to receive a charge of material therefrom and releasing saidcharge holder for movement to said mold, connections for operating saidextruding apparatus when said charge holder is pressed against the sameand stopping the operation of the extruding apparatus when said chargeholder is withdrawn therefrom, and a pressure member which forces saidpiston into said cylinder to eject material from said charge holder andinject the same into said mold when said charge holder is in operativerelation to said mold.

3. A method of injection molding plastic ma terials, which includesmoving a series of charge holders so that one charge holder is in chargereceiving position while another charge holder is in injection moldingposition, successively moving each of a series of molds into injectionmolding position, forcing a charge of molding material in excess of thatrequired into a charge holder while in charge receiving position,forcing most of the molding material contained in a charge holder into amold While in injection position, moving each charge holder afterinjection of material therefrom into another position, and removing fromthe charge holder while in said other position any molding materialremaining in said charge holder.

4. In a machine for injection molding plastic materials, the combinationof a turret having a plurality of molds mounted thereon and movableintermittently to successively place the molds thereon into moldingposition, an extruding apparatus for extruding material to be molded, anintermittently rotatable member having a plurality of charge holdersmounted thereon, to move with said rotary member and also rela tivelythereto, mechanism for imparting intermittent rotary motion to saidrotary member to move one of said charge holders into proximity to saidextruding apparatus and another charge holder into operative relation toa mold, mechanism for 'rnoving said first mentioned charge holderrelatively to said rotatable member into charge receiving relation tosaid extruding apparatus, control mechanism for actuating said extrudingapparatus for extruding material to be molded into a charge holder whilein charge receiving relation to said extruding apparatus, and means forfirst moving said charge holders relatively to said rotatable memberinto injecting relation to a mold and then for forcing the material fromsaid other charge holder into a mold.

5. In a machine for injection molding plastic materials, the combinationof a turret having a plurality of molds mounted thereon and movableintermittently to successively place the molds thereon into moldingposition, an extruding apparatus, a rotary member having a plurality ofcharge holders mounted thereon to move with said rotary member and alsorelatively thereto and constructed to simultaneously present one of saidcharge holders to said extruding apparatus and another charge holderinto proximity to a mold on said turret, means for simultaneouslyrotating said turret and said rotatable memher for positioning differentmolds and charge holders in operative relation to each other, means forextruding material to be molded from said extruding apparatus into acharge holder in operative relation thereto, and mechanism for moving acharge holder positioned in proximity to a mold relatively to saidrotary member against a mold and for forcing material from said chargeholder into a mold.

6. In a machine for injection molding plastic materials, the combinationof a mold an extruding apparatus for discharging plastic material to bemolded, a charge holder including a cylinder and a piston, a movablemember on which said charge holder is carried for movement between saidextruding apparatus and said mold, a guide on said movable member onwhich said charge holder is movable in the direction of its length,means for moving said charge holder relatively to its guide intooperative relation to answersaid extruding apparatus to receive a chargeof material to be molded therefrom, means for said mora le member toplace said charge into operative relation to said mold, and fordischarging material from said charge i into said mold.

'2. In a machine for injecti n molding plastic materials, thecombination of a mold, an extru'd-- ing apparatus for dischargingplastic material to be in led, a charge holder including a cylinder 1 ia piston, a movable member on which said s holder carried for movementbetween extrudin apparatus and sold mold, a guide vablfi member on whichsaid charge ovable in the direction of its length,

means for moving said charge holder relatively to s into operativerelation to said extrudtus to receive a charge of material to therefrom,means for moving said movable member to place said charge holder intooperative relation to said mold, and means for applying presure to thepiston of said charge holder for 'lscharging material from said chargeholder into said mold.

8. In a machine for injection molding plastic naterials, the combinationof a mold, an extruding apparatus for discharging plastic material to bemolded, a charge holder including a cylinder and a piston, a movablemember on which said charge holder is carried for movement between saidextruding apparatus and said mold, a guide on said movable member onwhich said charge hol or is movable in the direction of its length,means for moving said charge holder relatively to its guide intooperative relation to extruding apparatus to receive a charge of mate'rial to be molded therefrom, means for moving said movable member toplace said charge holder into operative relation to said mold, and meansfor applying pressure to the piston of said charge holder for movingsaid charge holder lengthwise of its guide into operative relation tosaid mold clue to friction between said material and said cylinder, andfor moving said piston into said cyl inder to discharge material fromsaid charge holder into said mold.

9. An injection molding machine according to claim 7, and includingyielding means for urgin said charge holder relatively to its guide in adirection away from said mold and said extruding apparatus.

10. In a mach ne for injection molding plastic materials, thecombination ofa mold, an extruding apparatus for the material to bemolded, a plurality of charge holders for receiving material from saidextruding apparatus and discharging the same into Said mold, a rotarymember on which said charge holders are mounted and whichis rotatable tomove said charge holders from said extruding apparatus to said mold andhaving guides for said charge holders in which said charge holders mayslide toward and from said extruding apparatus said mold, means formoving said charge holders one at a time relatively to said guides intooperativerelation to said extruding apparatus to receive a charge ofmaterial therefrom, and a pressure member arranged to apply pressure tosaid charge holders for moving the same relatively to said guidesintoopemtive relation to said mold and for then discharging materialfrom said charge holders into said mold.

11. In a machine for injection molding plastic materials, thecombination of a mold, an extrud ing apparatus for the material to bemolded, a

charge holder for receiving acharge' of materiat from said extrudingapparatus, a movable memher on which said charge holder is mountedandwhich is movable toplace said charge holder into operative" relation tosaidextruding apparatus and said mold, a guide on said movable member onwhich said charge holder is movable toward said extruding apparatus andtoward said mold, means for moving said charge holder relatively to saidmovable member into charge receivingposition relatively to' saidextruding apparatus;- and a pressure member mounted to engage saidcharge holder to move'the same relatively to saidguide into position inengagement with said mold for the discharge of material into said mold,saidcharge holder including a cylinder and a piston reciprocabletherein, said pressure member act-' ing on said piston and injectingmaterial fromsaid charge holder into said mold.

12. A molding machine according, to claim 11, in which said chargeholder has a" part for guid ing the movement of said piston into and outof said cylinder.

13; A molding machine according to claim 1-1, characterized in that saidguide has a portion for limiting movement of said piston outwardly withreference to said cylinder.

14. A machine for injection molding plastic materials, including anextruding apparatus for discharging material to be molded, a chargeholder for receiving a charge of material from said extruding apparatus,a movable'member on which said charge holder is movably mounted andwhich moves said charge holder to and from said extruding apparatus anda molding position, a part mounted on said extruding apparatus and apart on said charge holder, said parts moving into proximity to eachother when said charge holder is moved to said extruding apparatus,means for actuating said part on said extruding apparatus to move saidcharge holder relatively tosaid mov able member" into engagement withsaid' extrud ing a paratus to receive a charge of material therefrom andfor releasing said charge holder from engagement with said extrudingapparatus when a charge of material has been extruded into said chargeholder, and means for ejecting ma-- terial from said charge holder underpressure for molding the same when said charge holder has been movedinto molding position.

15. A machine for injection molding plastic materials, including anextruding apparatus for discharging material to be molded, a chargeholder for receiving acharge of material from said extruding apparatus,a movable member on which said charge holder is'movably mounted andwhich moves said charge holder to and from proximity to said extrudingapparatus and a charge eject ing position, a lever mounted on saidextruding apparatus and having a projection, said charge holder having apart movable into operative relation to said projection of said leverwhen said charge holder has been moved by said movable member intoproximity to said extruding apparatus, and means for swinging said leverto move said charge holder into engagement with said extruding apparatusto receive a charge of material therefrom, and for swinging said leverin the opposite direction when said charge holder has received materialfrom said extruding apparatus.

16. A machine for injection molding plastic materials, including anextruding apparatus for discharging mater al to be molded, a chargeholder for receiving a charge .ofmaterial from"

